Random Natural History: Valley Oaks and their Galls.

Ok, time for a short bit of natural history. I live in the Sacramento Valley in northern California. The dominant tree species (outside of urban areas) seems to be the Valley Oak (Quercus lobata). Now, there aren’t a whole lot of trees in the valley, so it’s pretty lucky that Valley Oaks are fairly spectacular.

Valley oak (Quercus lobata) on Joseph D Grant County Park Canada de Pala Trail

They are also little ecosystems unto themselves. The first thing most people notice about them are oak apple galls, so called because they bear a disturbing resemblance to (rotting) apples.

"Oak apple" galls of California Gall Wasps (Andricus quercuscalifornicus, Cynipidae, Hymenoptera) on Valley Oak (Quercus lobata, Fagaceae)

Trees can often be so laden with them that they actually look like cultivated apple trees. The galls are woody, though, not squishy like actual apples. What is a gall, you ask? Good question. A gall is essentially a plant tumor. In many cases (as here) galls are caused by insect parasites. An adult insect lays eggs in the tissue of a plant, and those eggs release hormones that induce the plant to form the gall. Galls can provide food and shelter for their hosts until they are ready to mate and lay new eggs. Galls can be quite complicated structures, the result of parasites evolving very refined control over their hosts over time. As a result, galling insects can frequently be identified by their galls alone. Oak apple galls are caused by a wasp, Andricus quercuscalifornicus, but are exploited by a constellation of at least 20 other arthropods that feed on the galls, A. quercuscalifornicus, and each other.

These aren’t the only galls associated with the Valley Oaks. There are at least two more. One of which is fairly bizarre and the original inspiration for this post: the California Jumping Gall. This gall is also caused by a wasp, Neuroterus saltatorius. In contrast to the oak apple galls, these galls are tiny, only about a millimeter across. What they lack in size, however, they make up for in quantity. These galls form on the undersides of oak leaves by the hundreds of thousands. When they mature, they drop off the leaves, wasp larva still inside. Once on the ground, they start “jumping”. The larvae violently fling themselves around inside the gall, presumably to try to move it into a sheltered spot where they can finish out their life cycle and emerge the following spring to lay new eggs.

The galls are dropping now in my neighborhood, and the result is that sidewalks and gutters under valley oaks appear to be full of jumping grains of sand. It’s a pretty weird sight:

Here’s a link to another video:

ARKive video - California jumping gall wasp - overview

Well, that’s all I’ve got for now. I’ll end on another photo of an amazing Valley Oak.

Quercus lobata VALLEY OAK/ROBLE

“One of the great migration stories of the world” – Shrimp in the mighty Mississippi.

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Macrobrachium ohione, by Clinton and Charles Robertson, via Flickr.

The Mississippi River that we know today is a creation of the army corps of engineers. Before they got to levying, dredging and damming it into submission, it was a wild and meandering thing that harbored great concentrations of wildlife. One component of that was a massively abundant shrimp with an amazing life cycle:

It turned out that in pre-colonial times the shrimp traveled all the way north into the upper reaches of the Mississippi’s main eastern tributary, the Ohio River, and back again – a 2,000-mile round trip. It was a journey more amazing than similarly epic migrators like salmon. For whereas adult salmon may have an equally long journey to their upstream spawning sites, it is the quarter-inch juvenile shrimp that swim and crawl 1,000 miles upstream against the strong currents of the Mississippi.

What happened to these shrimp? Go read the story to find out.

Adjunctivitis

View from Kamiak Butte. Outside Moscow, ID.

View from Kamiak Butte. Outside Moscow, ID.

A lot of pixels have been spilled on the subject of the adjunct crisis in academia. For those of you who don’t know what that is, it refers to the explosive growth in the use of adjunct faculty to teach courses at colleges and universities in the United States. These faculty are hired on a course by course, semester by semester basis. They receive no benefits and don’t have a shred of job security. By some estimates an average “full-time” adjunct faculty member teaching 8 courses a year (3 each semester and 2 in the summer, perhaps?) would make less than $30,000 a year and it’s thought that adjunct faculty are now doing 70% of the teaching at higher education institutions in the US.

Much of the discussion of this issue has focused on the perceived fundamental unfairness of employing highly educated professionals in such an absurd fashion, or on the pyramid scheme-y aspects of graduate programs that chew up students and spit them into this cesspool of underemployment. In the comments sections of these pieces, there is an ever-present retort, presumably emanating from those free market-loving capitalists among us, that if adjunct faculty hate their plight so much, they should change career paths.

In response to this, I want to use a recent post at this blog to highlight a slightly less well covered aspect of the issue and the other side of that coin: when you offer shitty compensation, you might just get shitty employees.

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Friday Coffee Break

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Here’s what we’ll be talking about while we wait in line for a latte:

The latest news in the human-neanderthal hybridization story: some neanderthal genes may have contributed to human adaptation during the expansion out of Africa. From Amy.

Anemones have been discovered living attached to antarctic sea ice. From Amy.

Rattlesnakes in the southwest have astoundingly variable venom. The variation confounds attempts at developing antivenoms and its adaptive significance is unknown. From Jeremy.

Did we learn nothing from Jurassic Park? The strain of Yersinia pestis that caused one of the worst plagues in human history has been extracted from a preserved tooth of one of its victims and had it’s genome sequenced. From Sarah.

A link containing a video of a flying snake. What more could you ask for? From Noah.

Think your tilapia-tomato aquaponic system is clever? Well the three-toed sloth has got you beat. It’s running an algae-moth system in its fur. From Noah.

Friday Coffee Break

Here’s what we’ll be talking about while we wait in line for a latte (and ^^^ is what we’ll be doing when we read the links):

A new amazonian river dolphin species discovered! From Noah.

Not biology, but… Yale student fight with their administration over use and display of course evaluation data. From Noah.

Everyone loves a nice juicy taxonomy fail. Don’t know what a salp is? Neither do a whole bunch of people writing stories about them on the internet. From CJ.

Mantis shrimp, best known for rapidly producing enormous amounts of force with their claws also have a unique and somewhat mysterious visual system. From CJ.

8 ways animals survive the winter. From Sarah.

Antibiotic resistance defined. From Sarah.

An absurd PLOS ONE paper presents the “quilt plot” which is really just a simple heatmap… but it spurs Lior Pachter to ask just what measures should go into a heatmap comparing gene expression data sets. From Noah.

Amateur ornithologists banding hummingbird (particularly in Louisiana!) have helped show that many species successfully winter year after year on the gulf coast. From Noah

Friday Coffee Break

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Here’s what we’ll be talking about while we wait in line for a latte:

How to get ants to carry a sign for you. From Jeremy.

Amazonian builder of mysterious tiny picket fences sort of discovered. From Amy.

Scientific meetings feature more women speakers when women are included in the organizing committees. From Sarah.

PLOS ONE papers that made the news in 2013. From Sarah.

A personal account of growing up unvaccinated in the 1970s. From Jeremy.

Even tiny roads built through amazon rainforest disrupt canopy-dwelling frog communities. From Noah.

On the evolution of blind cave fish.

Astyanax mexicanus cave dwelling form.

Evolution requires variation in traits among individuals to act. If evolutionary fitness is determined by a given trait, and everyone in a population has the trait, then there is no basis for natural selection to discriminate among individuals. Furthermore, when variation does exist, it must be genetically based so that it can be passed down by successful parents to their offspring. The trait variation on which selection acts can either come from genetic variation existing in a population before selection begins or it can result from new mutations. Because natural selection acts to eliminate unfavorable variation, there is a question as to how selection in a changing environment could reverse change, or remove a trait it had previously favored. Where would the necessary variation come from?

One controversial hypothesis is that genetic variation for a given trait can be masked from selection by very stable (or “canalized”) developmental processes. These canalized processes result in highly uniform traits within a population despite underlying genetic variation. Under certain environmental conditions (in particular, stressful ones), they can be destabilized, allowing underlying genetic variation to cause traits to vary, thus providing grist for natural selection’s mill.

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Friday Coffee Break! Jules-likes-the-links Edition.

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Here’s what we’ll be talking about while we wait in line for a latte:

Are you unreasonably paranoid about germs? New proposals by the FDA  may add a lot of stress to your life. The rest of us, however, should be quite happy about them.

A discussion of the ecological “ghosts” of extinct birds in the ecosystems they inhabited.

A pair of videos about urgent environmental issues utilizing very effective visuals, one on road building and deforestation and a second on overfishing.

A NEW TAPIR species has been discovered. When a 100kg mammal flies under science’s radar for so long (local indigenous people knew it was different all along…) you know we have a terrible grasp of earth’s biodiversity.

This week in genetics/popular science controversies: DNA sequence motifs that regulate gene expression are found to overlap with sequences coding for proteins far more frequently than previously thought. This may explain some prominent and heretofore mysterious features of protein coding DNA. An unfortunate attempt at coining a new term (“duon”) and blundering PR campaign about the work inspire some stinging rebukes.

Friday Coffee Break: You talkin’ to me? You talkin’ to me!?

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Here’s what we’ll be talking about while we wait in line for a latte:

War. War never changes. Argentinian mockingbirds brutally attack brood parasitic cowbirds, but fail to stop them from laying eggs. -From Noah.

ARE THE MEATS AND CHEESES YOU LOVE ALTERING YOUR GUT MICROBIOTA TO MORE CLOSELY RESEMBLE THAT OF LAB MICE WHO ARE SIGNIFICANTLY MORE LIKELY TO SUFFER VARIOUS AILMENTS, AND THEREFORE KILLING YOU?! FOR THE LOVE OF GOD, CLICK THIS LINK TO FIND OUT BEFORE ITS TOO LATE! -From Sarah.

But Wait! There’s More! The jet-propulsion butt-hydraulic system also is a gill.” -From Jeremy, who tells me that Apple and Samsung are currently waging a high-stakes patent battle over the butt-hydraulics to be included in the next generation of smart phones. 

Finally, in keeping with the belligerent theme: David Dobbs writes an adversarial piece on the concept of the selfish gene and Richard Dawkins and Jerry Coyne rebuff it. Meanwhile, Michael Behe [link redacted] says something that makes everyone ask “Must creationist effluvia befoul every. single. google search I do for this blog?”

Friday Coffee Break: Just what is a Denisovan Anyway?

They’ll never believe you.

Here’s what we’ll be talking about while we wait in line for a latte.

From Sarah: Drug cartels and academia share similarly structured labor markets.

…and in that cynical vein, a statistical analysis using professors’ last names that shows nepotism is a significant force in Italian universities.

From Noah: A new record is set in ancient human DNA sequencing: 400 thousand year old hominid DNA has been successfully sequenced. The results suggest previously unknown complexity in human history, and that we don’t really know what, exactly, the Denisovans were. Or at least they suggest that Noah doesn’t know.

It’s an old reference, but it holds up: check out this ten year old David Foster Wallace essay, “Consider the Lobster“. For an article in a food magazine, it sure has a lot of interesting lobster biology in it.

We may be late to the party on this one, but there has been some interesting debate about the role the FDA should have in human genetic testing, particularly as it relates to the company 23andme’s direct-to-consumer model. Here is Michael Eisen’s take. Also, a blog post on the statistical issues associated with large scale screening for disease-associated genotypes has generated some interesting discussion (23andme genotypes are all wrong).

Meanwhile, 23andme has decided to stop offering health-related interpretation of the genotype data they provide.